Cadexomer iodine effectively reduces bacterial biofilm in porcine wounds ex vivo and in vivo

Abstract

Biofilms are prevalent in non‐healing chronic wounds and implicated in delayed healing. Tolerance to antimicrobial treatments and the host's immune system leave clinicians with limited interventions against biofilm populations. It is therefore essential that effective treatments be rigorously tested and demonstrate an impact on biofilm across multiple experimental models to guide clinical investigations and protocols. Cadexomer iodine has previously been shown to be effective against biofilm in various in vitro models, against methicillin‐resistant Staphylococcus aureus biofilm in mouse wounds, and clinically in diabetic foot ulcers complicated by biofilm. Similarities between porcine and human skin make the pig a favoured model for cutaneous wound studies. Two antiseptic dressings and a gauze control were assessed against mature biofilm grown on ex vivo pig skin and in a pig wound model. Significant reductions in biofilm were observed following treatment with cadexomer iodine across both biofilm models. In contrast, silver carboxymethylcellulose dressings had minimal impact on biofilm in the models, with similar results to the control in the ex vivo model. Microscopy and histopathology indicate that the depth of organisms in wound tissue may impact treatment effectiveness. Further work on the promising biofilm efficacy of cadexomer iodine is needed to determine optimal treatment durations against biofilm.

In vitro Activity of Antimicrobial Wound Dressings on P. aeruginosa Wound Biofilm

“…The obtained results of the investigated wound dressings regarding antimicrobial efficacy partly contrast what is currently considered best-practice knowledge and has been previously reported. In case of the iodine-containing product (C-IOD), a distinct and continuous antimicrobial effect was observed in this study with a successive microbial reduction within 3 days (Figure 2), confirming previous in vitro and clinical studies (Phillips et al, 2015;Fitzgerald et al, 2017;Roche et al, 2019). It should be emphasized, however, that under treatment with the cadexomer-iodine dressing, the biofilm model was not completely dissolved in bromelain.…”

Priority effects dictate community structure and alter virulence of fungal-bacterial biofilms

“…Fungal-bacterial interactions alter biofilm structure and spatial organization within ex vivo human skin wounds Unlike uniform in vitro models utilizing synthetic materials, a human skin ex vivo wound model allows us to investigate biofilm architecture of single, dual, or three-member communities across the spatially structured environment and heterogenous biotic substrate represented by human skin [59][60][61][62][63][64] using scanning electron microscopy (SEM). With this model, priority effects, or the impact of an early colonizer on a later colonizer within a community [65][66][67] were tested under three conditions.…”

Letters

“…This positive statement by the Cochrane group has led to the recommendation of CI as standard of care for treatment of VLU's in guidelines. 8 To conclude, the beneficial use of Cadexomer iodine in VLU's is supported by the highest level of evidence clinically, and its efficacy against biofilms is demonstrated across a plethora of challenging in vitro and animal biofilm models [9][10][11] and in DFU's. 12,13 We are disappointed in the shortfalls of the manuscript by Scully et al highlighted in this response but hope this clarification will allow clinicians to make a more balanced judgement in treatment choices for hard-to-heal wounds.…”