Cellular Effects Nanosilver on Cancer and Non-cancer Cells: Potential Environmental and Human Health Impacts

Nanosilver is extremely small silver particles (1-100 nm in diameter) and have antimicrobial, antifungal, and antiviral properties, which make them one of the most commonly used nanoparticles. There is a lack of biological and toxicological knowledge on the impacts of nanosilver on cellular stress responses, as well as human and environmental health. Nanosilver and ascorbic acid has the potential to be an anticancer therapeutic. In this study, human colon cancer (HCT116) and intestinal epithelial (HIEC-6) cells were used to study nanosilver effects in cancer versus non-cancer cells. Nanosilver increased Nrf2 protein expression and disrupted the cell cycle at the G1 and G2/M phases. Hypoxia attenuated nanosilver-induced oxidative and endoplasmic reticulum stress responses. Nanosilver induced significant mitochondrial oxidative stress in HCT116, whereas it did not in the non-cancer HIEC-6 and nanosilver/sodium ascorbate co-treatment was preferentially lethal to HCT116 cells, which is promising for further research for anticancer therapies.