Degree of the Hazards of Silver-Containing Dressings on MRSA-Infected Wounds in Sprague-Dawley and Streptozotocin-Induced Diabetic Rats

Abstract

Silver-containing dressings are commonly used on healing wounds, including diabetic ulcers. Some studies have shown that dressing materials with silver have negative effects on wound healing, specifically, that the wound healing process is inhibited by deposited silver. Therefore, the authors treated wounds infected with methicillin-resistant Staphylococcus aureus (MRSA) in Sprague-Dawley (SD) rats and streptozotocin (STZ)-induced diabetic rats with silver dressings to evaluate the risks of silver. Materials and Methods. The study used 54 SD rats and 54 STZ-induced diabetic rats. Full-thickness skin defects were created in all animals and then infected with MRSA. The rats were divided into 6 groups according to the dressing materials: nanocrystalline silver (Ac) (ACTICOAT, Smith and Nephew Healthcare, Hull, UK), silver carboxymethylcellulose (Aq) (AQUACEL Ag, ConvaTec, Bristol-Myers Squibb, Skillman, NJ), silver sulfadiazine (M) (Medifoam Silver, Biopol Global Co, Ltd, Seoul, Korea), nanocrystalline silver (P) (PolyMem Silver, Ferris Mfg Corp, Fort Worth, TX), Ilvadon cream (I) (IIdong Pharaceutical Co, Ltd, Seoul, Korea), and 10% povidone iodine (B) (Betadine, Sung Kwang Pharmaceutical Co Ltd, Gyeonggi-Do, Korea) as a control agent. Blood was collected from all animals to measure the hematological effects. The skin, spleen, liver, and kidneys of each rat were biopsied and used to make paraffin sections in which the silver deposition was measured using energy-dispersive spectrometry (EDS). Results. Fifteen days after wounding, only the Ac, P, and I groups differed significantly (P < 0.05) from the B group. The glutamic-oxaloacetic transaminase, blood urea nitrogen, and alkaline phosphatase levels differed significantly (P< 0.05) between the SD and STZ rats. No silver deposition was found in any organ. Conclusion. The silver dressings induced slight liver damage in the STZ-rats. Although changes in serum chemistry caused by silver were seen, this did not indicate silver deposition in the organ as the EDS did not show excess levels. The risk of silver deposition appears to be low. The hazards of silver-containing dressing products in MRSA-infected wounds were insignificant.