The Role of a Silver Releasing Lipido-colloid Contact Layer in Venous Leg Ulcers Presenting Inflammatory Signs Suggesting Heavy

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Author(s): 
Isabelle Lazareth, MD;1 Sylvie Meaume, MD;2 Michèle Léa Sigal-Grinberg, MD;3 Patrick Combemale, MD;4 Thierry Le Guyadec, MD;5 Anne Zagnoli, MD;6 Jean-Luc Perrot, MD;7 Anne Sauvadet, PhD;8 Serge Bohbot, MD8

Disclosure: This study was funded by a grant from URGO Laboratories, France. Dr. Meaume and Dr. Lazareth have served as paid speakers for URGO Laboratories. Dr. Sauvadet and Dr. Bohbot are employees of URGO Laboratories.

Nearly all open wounds are contaminated by microorganisms, but this generally corresponds to a simple bacterial growth without leading to deleterious effects or compromising the progress of the healing process. If the probability of wound infection increases as the level of contamination does in acute wounds, it is more complex for chronic wounds which are able to content and tolerate without inducing local signs, large amounts of bacteria, many times higher than the usual threshold level (≥ 105 bacteria/g of tissue) defining infection in acute wounds.1 Nevertheless, many clinical and experimental studies indicate that the probability for chronic wounds to heal properly is limited when the bacterial load exceeds this level of contamination; even when body defenses are still able to prevent tissue invasion, bacteria can impair wound healing.2–11 Numerous mechanisms are involved in wound stagnation due to this bacterial growth: local release of endotoxins and exotoxins, of pro-inflammatory cytokines, local pH alteration, decrease in oxygen supply and increased MMPs/TIMPs (metalloproteinases/tissue inhibitor of metalloproteinases) ratio notably.10,12 This prolongs an inappropriate topical inflammatory reaction, which contributes to delay the wound healing process.

These considerations are theoretical grounds to support the use of silver in chronic wounds when a negative local impact of bacterial colonization is confirmed or suspected. Indeed, silver is a large spectrum antibacterial agent which covers virtually all the bacterial strains responsible for chronic wound colonization (including resistant species such as MRSA) with a weak toxicity against fibroblasts.13–15 Furthermore, this metallic ion has strong anti-inflammatory properties, inhibits MMP activity and promotes apoptosis of senescent cells.16–18 There is very little risk of seeing resistance develop to the silver ion because its mechanism of action involves many membrane- and nucleus-based sites.19

Despite widespread use of silver ions in the management of chronic wounds, the clinical interest of silver in these wounds is not yet fully established.20 The main objective of this randomized clinical study was to evaluate the ability of a new silver releasing wound dressing to promote the healing process of venous leg ulcers presenting inflammatory signs suggesting a heavy bacteria colonization, when compared to the same wound dressing not impregnated with silver salts.

References: 

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