Cytotoxicity testing of silver-containing burn treatments using primary and immortal skin cells

A novel burn wound hydrogel dressing has been previously developed which is composed of 2-acrylamido-2-methylpropane sulfonic acid sodium salt with silver nanoparticles (silver AMPS). This study compared the cytotoxicity of this dressing to the commercially available silver products; Acticoat (TM), PolyMem Silver (R) and Flamazine (TM) cream. Human keratinocytes (HaCaT and primary HEK) and normal human fibroblasts (NHF) were exposed to dressings incubated on Nunc (TM) polycarbonate inserts for 24, 48 and 72 h. Four different cytotoxicity assays were performed including; Trypan Blue cell count, MTT, Celltiter-Blue (TM) and Toluidine Blue surface area assays. The results were expressed as relative cell viability compared to an untreated control. The cytotoxic effects of Acticoat (TM) and Flamazine (TM) cream were dependent on exposure time and cell type. After 24 h exposure, Acticoat (TM) and Flamazine (TM) cream were toxic to all tested cell lines. Surprisingly, HaCaTs treated with Acticoat (TM) and Flamazine (TM) had an improved ability to survive at 48 and 72 h while HEKs and NHFs had no improvement in survival with any treatment. The novel silver hydrogel and PolyMem Silver (R) showed low cytotoxicity to all tested cell lines at every time interval and these results support the possibility of using the novel silver hydrogel as a burn wound dressing. Researchers who rely on HaCaT cells as an accurate keratinocyte model should be aware that they can respond differently to primary skin cells. (C) 2014 Elsevier Ltd and ISBI. All rights reserved.