The cytotoxicity of silver nanoparticles coated with different free fatty acids on the Balb/c macrophages: an in vitro study.

Nanoparticles (NPs) can adsorb different molecules, because of their high local charge density and specific surface area. The toxicity of NPs is changed after adsorption, which may be different from unbound or unbound NPs. In this study, unbound silver nanoparticles (Ag NPs) and Ag NPs coated with different free fatty acids (FFAs) including lauric acid, alpha linoleic acid, oleic acid, and palmitic acid were incubated with mouse macrophages for 24 hours at 37 °C. After incubation, their toxicities, reactive oxygen species (ROS) generation, and uptake were separately investigated. This study showed that FFA-coated Ag NPs had less toxicity, higher uptake, and less ROS generation than unbound Ag NPs. Based on the results, unbound Ag NPs aggregated in RPMI1640 medium, and their size distribution was near 100-1000 nm. But all FFA-coated Ag NPs had nano metric size (near 20--40 nm) without agglomeration.