Cytotoxicity of silver dressings on diabetic fibroblasts

Abstract

A large number of silver-based dressings are commonly used in the management of chronic wounds that are at risk of infection, including diabetic foot ulcers. However, there are still controversies regarding the toxicity of silver dressings on wound healing. The purpose of this study was to objectively test the cytotoxicity of silver dressings on human diabetic fibroblasts. Human diabetic fibroblasts were obtained from the foot skin of four diabetic foot ulcer patients and cultured. The effect of five silver-containing dressing products (Aquacel Ag, Acticoat*Absorbent, Medifoam Ag, Biatain Ag and PolyMem Ag) and their comparable silver-free dressing products on morphology, proliferation and collagen synthesis of the cultured human diabetic fibroblasts were compared in vitro. In addition, extracts of each dressing were tested in order to examine the effect of other chemical components found in the dressings on cytotoxicity. The diabetic fibroblasts cultured with each silver-free dressing adopted the typical dendritic and fusiform shape. On the other hand, the diabetic fibroblasts did not adopt this typical morphology when treated with the different silver dressings. All silver dressings tested in the study reduced the viability of the diabetic fibroblasts and collagen synthesis by 54-70 and 48-68%, respectively, when compared to silver-free dressings. Silver dressings significantly changed the cell morphology and decreased cell proliferation and collagen synthesis of diabetic fibroblasts. Therefore, silver dressings should be used with caution when treating diabetic wounds.

Management of large chronic venous leg ulcers with negative pressure wound therapy

“…23 Despite its advantages in treating infected wounds, silver has been demonstrated to be cytotoxic to human keratinocytes and fibroblasts in vitro. 21,24 However, the clinical correlation to support this finding remains unclear. 22,25 Some authors suggest that the human body has complex homeostatic mechanisms and silver might have different effects in vivo than in vitro.…”

“…The usefulness of silver as an antimicrobial agent has been known since antiquity and is well established. 21 The antimicrobial effect of silver is mediated by the presence of the highly reactive Ag + cation which is disruptive to many aspects of microorganism metabolism. The mechanism of action includes damage to the bacterial cell wall, blockage of transport and enzyme systems such as the respiratory cytochromes, alteration of proteins and binding of microbial deoxyribonucleic acid and ribonucleic acid to prevent transcription and division.…”

In Vitro Parallel Evaluation of Antibacterial Activity and Cytotoxicity of Commercially Available Silver-Containing Wound Dressings

“…High cytotoxicity of these Ag dressings has been demonstrated in previous reports. 18,20 It has been reported that silver was dissociated from Aquacel Ag in contact with body fluids. 28 The nonwoven fabric substrates show rapid uptake of environmental liquids and diffusion of solutes, accelerating the diffusion of Ag by the chemical properties of the silver compounds and the physical properties of the polymeric substrates.…”

“…11,12 Clinical evidence on Ag dressings has accumulated from clinical trials on patients with intractable ulcers, 13,14 resulting in an international 15 Despite the beneficial effect of silver, some adverse effects of topical silver on wound healing have also been described. [16][17][18] Delayed wound healing has been explained by cytotoxic effects and histological damage resulting from excessive Ag + release to wound sites. 19 Cytotoxic effects of silver have been demonstrated by in vitro and in vivo studies, in diabetic fibroblasts, 18 human HaCaT keratinocytes, 20 and in tissue culture and animal models.…”

“…[16][17][18] Delayed wound healing has been explained by cytotoxic effects and histological damage resulting from excessive Ag + release to wound sites. 19 Cytotoxic effects of silver have been demonstrated by in vitro and in vivo studies, in diabetic fibroblasts, 18 human HaCaT keratinocytes, 20 and in tissue culture and animal models. 21 Antibacterial activity and cytotoxicity are inherently in a trade-off relationship; therefore, the behavior of antibacterial silver in wound sites should be regulated, depending on the conditions of wounds, to achieve sufficient antibacterial activity while simultaneously minimizing cytotoxic effects.…”