Cytotoxicity Of Silver Dressings On Diabetic Fibroblasts

Background and objectiveA large number of silver based dressings are commonly used in the management of chronic wounds at risk of infection including diabetic foot ulcers. However, there are continual controversies about the toxicity of silver dressings on wound healing. Since silver is regarded as a broad spectrum agent and shows strong activity against gram positive bacteria which frequently colonized in chronic wounds in particular, it is commonly used in the management of chronic wounds at risk of infection including diabetic foot ulcers. While the primary purpose of topical antimicrobial agents is to reduce opportunities for infection by providing potent broad-spectrum antimicrobial activity, ideally, these agents should not compromise the activity of cells that are involved in the wound healing process. Especially, the issues of toxicity of dressings on host cells are important in diabetic ulcers which commonly show delayed or non-healing due to decreased cellular activity for wound healing. Moreover, there has been no publication which objectively studied toxicity of silver dressings on healing of diabetic wounds, in which silver dressings are commonly used.Objetive:The purpose of this study was to objectively test cytotoxicity of silver dressings on diabetic fibroblasts.Materials and methodsFive silver-contained dressing products (A-Ag, G-Ag, M-Ag, B-Ag, P-Ag) and their comparable silver-free dressing products (A, G, M, B, P) from the same manufacturers were purchased from company agents. Diabetic fibroblasts were obtained from foot skin of four diabetic foot ulcer patients who underwent debridement or toe amputations. In order to consider the effect of chemical components in the dressings on cytotoxicity, extracts of each dressing including silver were tested in vitro. Diabetic fibroblast cultures with dressings for 3 days, and then effect of five silver-contained dressing products and their comparable silver-free dressing products on morphology, proliferation, and collagen synthesis of human diabetic fibroblasts were compared. Statistical comparisons were performed by the paired t-test with p values< 0.05 being considered statistically significant by using a statistical software package (SPSS 13.0).ResultsThe extracts of the dressings tested in this study had similar electrolyte composition to the control extracts, except the concentration of calcium and silver.Diabetic fibroblasts treated with each silver dressing lost typical patterns of fibroblast morphology. All silver dressings tested in the study reduced viability of the diabetic fibroblasts and collagen synthesis by 54-70% and 48-68%, respectively, compared to silver free dressings.Conclusion1. Silver dressings have cytotoxicity on diabetic fibroblasts in vitro.2. Silver in the silver dressings is the main factor of cytotoxicity on diabetic fibroblasts.3. There are some relations between silver cytotoxicity and silver concentration in the silver dressings.