title: An in vitro test of the efficacy of an anti-biofilm wound dressing.
abstract: Broad-spectrum antimicrobial agents, such as silver, are increasingly being formulated into medicated wound dressings in order to control colonization of wounds by opportunistic pathogens. Medicated wound dressings have been shown in-vitro to be effective against planktonic cultures, but in-vivo bacteria are likely to be present in biofilms, which makes their control and eradication more challenging. Recently, a functional wound dressing (AQUACEL(®) Ag+ Extra™ (AAg + E)) has been developed that in addition to silver contains two agents (ethylenediaminetetraacetic acid (EDTA) and benzethonium chloride (BC)) designed to disrupt biofilms. Here, the efficacy of AAg + E is demonstrated using a biofilm model developed in an isothermal microcalorimeter. The biofilm was seen to remain viable in the presence of unmedicated dressing, silver-containing dressing or silver nitrate solution. In the presence of AAg + E, however, the biofilm was eradicated. Control experiments showed that neither EDTA nor BC alone had a bactericidal effect, which means it is the synergistic action of EDTA and BC disrupting the biofilm with silver being bactericidal that leads to the product's efficacy.
authors.affiliation: UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1 N 1AX, UK.
authors.forename: Jawal
authors.initials: J
authors.lastname: Said
authors.affiliation: ConvaTec GDC, First Avenue, Deeside Industrial Park, Deeside, Flintshire CH5 2NU, UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Walker
authors.affiliation: ConvaTec GDC, First Avenue, Deeside Industrial Park, Deeside, Flintshire CH5 2NU, UK.
authors.forename: David
authors.initials: D
authors.lastname: Parsons
authors.affiliation: UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1 N 1AX, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Stapleton
authors.affiliation: UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1 N 1AX, UK.
authors.forename: Anthony E
authors.initials: AE
authors.lastname: Beezer
authors.affiliation: UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1 N 1AX, UK. Electronic address: s.gaisford@ucl.ac.uk.
authors.forename: Simon
authors.initials: S
authors.lastname: Gaisford
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000494:pharmacology* / Q000627:therapeutic use; D001558:Benzethonium / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D018441:Biofilms / Q000187:drug effects*; D002266:Carboxymethylcellulose Sodium / Q000008:administration & dosage / Q000737:chemistry*; D004492:Edetic Acid / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D008826:Microbial Sensitivity Tests; D009779:Occlusive Dressings; D012834:Silver / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development; D014946:Wound Infection / Q000188:drug therapy* / Q000517:prevention & control; D014947:Wounds and Injuries / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents; D001558:Benzethonium; D012834:Silver; D004492:Edetic Acid; D002266:Carboxymethylcellulose Sodium
keywords: Biofilm; Isothermal calorimetry; Staphylococcus aureus; Wound dressings; silver