Design cytotoxicity: The effect of silver nanoparticles stabilized by selected antioxidants on melanoma cells

Silver nanoparticles (AgNPs) prepared and stabilized by diverse biologically active substances seem to be especially useful in diverse biological and medical applications. The combination of AgNPs with bioactive substances, such as antioxidants, can lead to the development of new systems of desired anticancer properties. In this research, AgNPs were prepared with the use of diverse antioxidant combinations including gallic acid (GA), (-)-epicatechin-3-gallate (EGCG), and caffeine (CAF). The insightful physicochemical characteristic revealed that each type of AgNPs exhibited spherical shape, comparable size distribution and negative surface charge. Surface-enhanced Raman spectroscopy (SERS) delivered the information about the chemistry of AgNP stabilizing layers, which turned out to be a crucial factor tuning toxicity of AgNPs toward murine B16 melanoma cells (B16-F0) and human skin melanoma (COLO 679) cells. EGCGAgNPs were the most cytotoxic among all the investigated AgNPs. They strongly reduced the activity of mitochondria, damaged cell membrane integrity, and penetrated inside the cells causing DNA damage. In turn, the toxicity of GAAgNPs strongly manifested via the induction of oxidative stress in the cells. It was found that CAFGAAgNPs exhibited the lowest toxicity toward the melanoma cells, which proved that a proper combination of antioxidants enable to prepare AgNPs of differentiated toxicity. It was established that human skin melanoma cells were significantly more sensitive to AgNPs than the murine melanoma cells.