Selenium nanoparticles induced membrane bio-mechanical property changes in MCF-7 cells by disturbing membrane molecules and F-actin.

Selenium nanoparticles (Se NPs) have been served as promising materials for biomedical applications, especially for cancer treatment. The anti-cancer effects of Se NPs against cancer cells have been widely studied in recent years, but whether Se NPs can induce the changes of cell membrane bio-mechanical properties in cancer cells still remain unexplored. In this Letter, we prepared Se NPs for investigating the intracellular localization of Se NPs in MCF-7 cells and determined the effects of Se NPs on apoptosis and necrosis in MCF-7 cells. Especially, we reported for the first time about the effects of Se NPs on the bio-mechanical properties of cancer cells and found that Se NPs could remarkably decrease the adhesion force and Young's modulus of MCF-7 cells. To further understand the potential mechanisms about how Se NPs affect the bio-mechanical properties of MCF-7 cells, we also investigated the expression of CD44 molecules, the structure and the amounts of F-actin. The results indicated that the decreased adhesion force between AFM tip and cell membrane was partially due to the changes of membrane molecules induced by Se NPs, such as the down-regulation of trans-membrane CD44 molecules. Additionally, the decrease of Young's modulus of MCF-7 cells was due to the dis-organization and down-regulation of F-actin induced by Se NPs. These results collectively suggested that cell membrane was of vital importance in Se NPs induced toxicity in cancer cells, which could be served as a potential target for cancer treatment by Se NPs.