Synergistic cytotoxicity and antibacterial effects of the composites of silver nanoparticles and Lonicera japonica extract on human dermal fibroblast and Staphylococcus aureus

Abstract In this work we report the synthesis of composites of silver nanoparticles and Lonicera japonica extract. In vitro cytotoxicity of these composites was tested against human foreskin dermal fibroblasts and antibacterial activity tested against Staphylococcus aureus. At the highest concentration of 100 µg/ml, the composites containing 50% Ag nanoparticles and 50% honeysuckle extract were found to provide the greatest antibacterial effect, with minimal cytotoxic effect. The release of three reactive oxygen species (•OH, O2−, H2O2) and silver ions from the composites were studied to understand the synergistic effects. It is hypothesised that whilst all ROS play a pivotal role in antibacterial activity, O2− could be the most important species. We conclude that the composites of silver nanoparticles and Lonicera japonica extract could be an appropriate nanomedicine for medical applications, such as topical dermal dressings.