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Hydrofiber® Technology Aquacel Ag Antimicro

Aquacel® Ag dressing - Antimicrobial Activity

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On demand antimicrobial activity

Due to Hydrofiber® Technology, AQUACEL® Ag dressing is able to provide both effective exudate management, and control mechanism for delivering “on demand” antimicrobial activity within the dressing.1

AQUACEL® Ag dressing with Hydrofiber® Technology gels on contact with wound exudate, providing a balanced concentration and delivery of silver to kill pathogens within the dressing, as demonstrated in vitro. In addition, the dressing is designed to provide effective concentrations of ionic silver at the wound-dressing interface. In effect, AQUACEL® Ag dressing acts as “a reservoir of silver” and responds to changes in the components of wound fluid with increased silver ion availability.1

”…the silver present is ionic and must dissociate from the dressing prior to becoming bioavailable… Two immediate advantages of this effect would be the lack of excess availability of the silver, which allays fears of potential toxicity to the patient and an extended period of time over which the dressing is bactericidal.”2

Broad spectrum activity1

AQUACEL® Ag dressing has been shown to provide effective antimicrobial activity against a large range of aerobic, anaerobic, and antibiotic resistant micro-organisms.

  • Staphylococcus aureus (NCTC 8532)
  • Staphylococcus aureus (clinical isolate)
  • Pseudomonas aeruginosa (clinical isolate, x2 strains)
  • Enterobacter cloacae (clinical isolate)
  • Streptococcus pyogenes (clinical isolate)
  • Klebsiella pneumoniae (clinical isolate, x3 strains)
  • Enterococcus faecalis (clinical isolate)
  • Escherichia coli (NCIMB 8545)
  • Escherichia coli (NCIMB 10544)
  • Acinetobacter baumannii (NCIMB 9214)
  • MRSA (NCTC 10442)
  • MRSA (NCTC 12232)
  • MRSA (clinical isolate, x 8 strains)
  • VRE (NCTC 12201)
  • VRE (clinical isolate, x 2 strains)
  • Serratia marcescens (clinical isolate)
  • Pseudomonas aeruginosa (NCTC 8506)
  • Bacteroides fragilis (clinical isolate)
  • Peptostreptococcus anaerobius (clinical isolate)
  • Clostridium ramosum (clinical isolate)
  • Clostridium clostridioforme (clinical isolate)
  • Clostridium cadaveris (clinical isolate)
  • Clostridium perfringens (clinical isolate)
  • Tissierella praeacuta (clinical isolate)
  • Candida albicans (NCPF 3179)
  • Candida albicans (NCPF 3265)

Rapid and sustained activity

  • The ionic silver in AQUACEL® Ag dressing starts killing a broad spectrum of pathogens, including MRSA, within 30 minutes of exposure to the dressing1
  • AQUACEL® Ag dressing provides sustained antimicrobial activity against aerobic, anaerobic (including antibiotic resistant strains), yeast and filamentous fungi for up to 14 days, as demonstrated in in vitro testing3

Kills bacteria within the dressing

Rapid Confocal Laser Scanning Microscopy4

 

t=0 minutes
A cross section of the AQUACEL® Ag dressing (~20-30μm) shows bacteria sequested within

t=40 minutes
As silver ions are made available in the dressing, bacteria are shown to be killed

t=100 minutes
After 100 minutes virtually all bacteria within the dressing can be seen to be killed

Rapid confocal laser scanning microscopy allows 'real-time' visualisation of bacterial sequestration within gelling AQUACEL® Ag dressings.
Using two special dyes, it is possible to show whether bacteria are alive (green) or dead (red) in the presence of silver ions.
 

References [+]

  1. Jones SA, Bowler PG, Walker M, Parsons D. Controlling wound bioburden with a novel silver-containing Hydrofiber® dressing.Wound Repair Regen. 2004;12:288–294.
  2. Gaisford S, Beezer AE, Bishop AH, Walker M, Parsons D An in vitro method for the quantitative determination of the antimicrobial efficacy of silver-containing wound dressings. Int J Pharm. 2009;366:111-116.
  3. Bowler PG, Jones SA, Walker M, Parsons D. Microbicidal properties of a silver-containing Hydrofiber dressing against a variety of burn wound pathogens. J.Burn Care Rehabil. 2004;25:192–196.
  4. Newman GR, Walker M, Hobot J, Bowler P. Visualisation of bacterial sequestration and bactericidal activity within hydrating Hydrofiber® wound dressings. Biomaterials. 2006;27:1129-1139.