In vitro toxicity of silver nanoparticles at noncytotoxic doses to HepG2 human hepatoma cells
In this clinical study, published in the journal Environmental Science & Technology in August 2009, silver nanoparticles were tested in very small concentrations on human hepatoma cell line HepG2 (a liver cancer cell line). The silver-treated cells were then compared to cells treated with polystyrene nanoparticles and silver carbonate (a chemical silver compound) in order to “test the toxic effects with respect to different raw chemical compositions and forms of silver.”
Interestingly, at very low concentrations of only one-half ppm, the silver appeared to accelerate cell proliferation. But at concentrations of 1 ppm and higher, the silver particles “induced abnormal cellular morphology” displaying “cellular shrinkage and acquisition of an irregular shape.” The researchers concluded that “both nanosized particles of silver as well as ionic silver contribute to the toxic effects of Ag-NPs” against the cancer cells.