Antiseptics for treating infected wounds: Efficacy on biofilms and effect of pH.

Biofilm recalcitrance is a persistent problem when managing difficult to heal and infected chronic wounds. The wound biofilm is a fundamental factor in the re-occurrence and delayed healing commonly observed in non-healing and infected chronic wounds. However, there is presently no single antimicrobial agent that is completely efficacious against both the planktonic and sessile polymicrobial communities evident in at risk or infected wounds. We will review currently available antimicrobials, with particular emphasis on silver and iodine, employed to help suppress biofilms in wounds. In addition, we will also review the effect of pH on antimicrobial efficacy. Available evidence suggests that it is best to take a multifactorial approach towards controlling biofilm in chronic, "at risk" and infected wounds. This highlights the growing importance of avoiding indiscriminate or inappropriate use of antimicrobials in the treatment of chronic wounds.

Clinical and Antibiofilm Efficacy of Antimicrobial Hydrogels.

Significance: Hydrogels have been shown to have a significant role to play in wound healing. Hydrogels are used to assist in the management of dry, sloughy, or necrotic wounds. However, recent scientific evidence has shown that biofilms delay wound healing and increase a wound propensity to infection. It is therefore essential that hydrogels incorporating antimicrobials demonstrate efficacy on biofilms. Consequently, it is the aim of this article to review the efficacy of hydrogels, incorporating antimicrobials, on wounds with specific reference to their efficacy on biofilms. Recent Advances: Technologies being developed for the management of wounds are rapidly expanding. In particularly next-generation hydrogels, incorporating copolymers, have been reported to enable the smart release of antimicrobials. This has led to the development of a more tailored patient-specific antimicrobial hydrogel therapy. Critical Issues: Evidence relating to the efficacy of hydrogels, incorporating antimicrobials, on biofilms within both the in vitro and in vivo environments is lacking. Future Direction: Studies that investigate the efficacy of antimicrobial hydrogel wound dressings on both in vivo and in vitro biofilms are important. However, there is a significant need for better and more reproducible in vivo biofilm models. Until this is possible, data generated from appropriate and representative in vitro models will help to assist researchers and clinicians in evaluating antimicrobial and antibiofilm hydrogel technology for the extrapolation of efficacy data relevant to biofilms present in the in vivo environment.

EDTA: An Antimicrobial and Antibiofilm Agent for Use in Wound Care.

Significance: Methods employed for preventing and eliminating biofilms are limited in their efficacy on mature biofilms. Despite this a number of antibiofilm formulations and technologies incorporating ethylenediaminetetraacetic acid (EDTA) have demonstrated efficacy on in vitro biofilms. The aim of this article is to critically review EDTA, in particular tetrasodium EDTA (tEDTA), as a potential antimicrobial and antibiofilm agent, in its own right, for use in skin and wound care. EDTA's synergism with other antimicrobials and surfactants will also be discussed. Recent Advances: The use of EDTA as a potentiating and sensitizing agent is not a new concept. However, currently the application of EDTA, specifically tEDTA as a stand-alone antimicrobial and antibiofilm agent, and its synergistic combination with other antimicrobials to make a "multi-pronged" approach to biofilm control is being explored. Critical Issues: As pathogenic biofilms in the wound increase infection risk, tEDTA could be considered as a potential "stand-alone" antimicrobial/antibiofilm agent or in combination with other antimicrobials, for use in both the prevention and treatment of biofilms found within abiotic (the wound dressing) and biotic (wound bed) environments. The ability of EDTA to chelate and potentiate the cell walls of bacteria and destabilize biofilms by sequestering calcium, magnesium, zinc, and iron makes it a suitable agent for use in the management of biofilms. Future Direction: tEDTA's excellent inherent antimicrobial and antibiofilm activity and proven synergistic and permeating ability results in a very beneficial agent, which could be used for the development of future antibiofilm technologies.

The Use of Silicone Adhesives for Scar Reduction.

Significance: This article discusses the history and developments of silicone gel sheeting (SGS) scar therapy. Furthermore, we review a breadth of literature to gain an insight into how and why topical silicone gels remain the favored treatment of medical experts in scar management. We also analyze an ever increasing number of alternative therapies claiming to provide enhanced scar reduction performance. Recent Advances: Topical silicone gel treatments seem to remain the first point of clinical recommendation in scar management. SGS has been used in scar therapy for over 30 years, during which its efficacy has been the subject of numerous clinical evaluations. Critical Issues: While the exact mechanisms by which SGS improves hypertrophic scars, keloid development and recovery are yet to be fully agreed upon, its ability to do so remains largely undisputed at present. However, there still is ongoing deliberation over the exact mechanism of action of silicone in improving a scar. At present it is likely that through occlusion of the scar site and hydration of the wound bed, the overactivity of scar-related cells is suppressed, and their activity normalized. Future Direction: The clinical support of topical silicone gel products, relative to all alternative scar therapies, is considered the internationally recommended first-line form of scar management, and favored by consensus among healthcare professionals. However, there still remains the need for further clinical evidence and a better understanding of the mechanism behind the benefit of silicone gel for use in the prevention of abnormal scarring.