Cytotoxicity evaluation of sub-10-nm silver colloid prepared by electrolytic synthesis procedure

Silver nanoparticles with smaller scales tend to exhibit higher cytotoxicity. In the present work, a mild electrolytic synthesis procedure is proposed and implemented for the preparation of sub-10-nm silver colloids in polarity organic solvent media by using the nonionic polymer as a stabilizer. The synthesized silver nanoparticles can be stably dispersed in salt, acid, and alkali dispersion media. The cell viability and cytotoxicity are investigated by fluorescein diacetate/propidium iodide double staining and thiazolium blue colorimetry in vitro. Under concentration-gradient and time-gradient tests, the synthesized silver nanoparticles exhibit significant cytotoxicity against the human hepatocellular carcinoma cells of HepG2 and the human non-small cell lung cancer cells of A549 at the exposure dose of 1.6 and 2.0 ug mL−1, respectively.