Characterization and evaluation of silver release from four different dressings used in burns care

For centuries silver and silver compounds have been in use to control infection and avoid septicaemia in the care of burns and chronic wounds. Renewed interest has resulted in a number of Ag based dressings that are now widely used in burns centres. Despite extensive use, a systematic study of the chemical composition, release kinetics and biochemical action of these products has yet to be published. In this work we have characterized the morphology of four commercial Ag dressings by scanning electron microscopy and the silver content was determined to range between 1.39 mg/cm2 and 0.03 mg/cm 2. Release kinetics in three different matrices (ultra pure water, normal saline solution and a human serum substitute) were determined. The highest rates were found in serum substitute, with a maximum of 4099 ?g/(h cm2) to a minimum of 0.0001 ?g/(h cm2). Our results show that the mean inhibitory concentrations are exceeded for most common pathogens in serum substitute and sterile water, but the presence of high Cl- concentrations tend to inactivate the dressings.