Toxicity and antimicrobial activity of a hydrocolloid dressing containing silver particles in an ex vivo model of cutaneous infection.
In the present study we examined the effects of two hydrocolloid wound dressings (conventional silver-free Comfeel, silver-incorporating Contreet-H) on uninfected and Candida albicans- or methicillin-resistant Staphylococcus aureus-infected reconstituted human epithelium (RHE). The morphological alterations of the keratinocytes caused by infection and by treatment were analysed with light and electron microscopy. As a measure of epithelial cell damage the release of lactate dehydrogenase from epithelial cells into the surrounding medium was monitored. Application of Contreet-H or Comfeel to uninfected RHE induced no major morphological effects on epithelial cells. Both wound dressings reduced the growth of micro-organisms. Specific alterations of the infected epithelium (vacuoles, spongiosis, oedema, detachment of keratinocytes) and invasion of the epithelium were significantly reduced only by treatment with Contreet-H. At the ultrastructural level release of silver by Contreet-H and superior antimicrobial efficacy could be verified. In summary, treatment with both wound dressings reduced the number of pathogens, with the silver-based wound dressing providing a more effective antimicrobial activity. This resulted in a strong decrease of pathogen-specific alterations of the infected epithelium. We present evidence that delivering silver to infected keratinocytes in a moist healing environment improves the benefit/risk ratio as compared to silver-free wound dressings.
Schaller
M
M
Department of Dermatology and Allergology, University of Munich, Frauenlobstrasse 9-11, DE-80337 Munich, Germany. Martin.Schaller@lrz.uni-muenchen.de
Laude
J
J
Bodewaldt
H
H
Hamm
G
G
Korting
H C
HC
D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D000935:Antifungal Agents / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D047070:Bandages, Hydrocolloid; D002176:Candida albicans / Q000187:drug effects; D003102:Colloids / Q000009:adverse effects; D004848:Epithelium / Q000187:drug effects / Q000382:microbiology; D006801:Humans; D066298:In Vitro Techniques; D015603:Keratinocytes / Q000187:drug effects / Q000382:microbiology; D016106:Methicillin Resistance; D008954:Models, Biological; D009779:Occlusive Dressings / Q000009:adverse effects; D018570:Risk Assessment; D012834:Silver / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D013211:Staphylococcus aureus / Q000187:drug effects; D014946:Wound Infection / Q000188:drug therapy* / Q000382:microbiology
D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D003102:Colloids; D012834:Silver