Cellular Toxicity Study of Silicon Nanowires

The objective of this study was to achieve the practical bioapplications of silicon nanowires (SiNWs). In this study, the tumor and normal cell lines were used as models to systematically investigate the cytotoxicity of SiNWs synthesized by HF-assisted etching methods. Morphology observation, Cell Counting Kit 8, real-time polymerase chain reaction, and flow cytometry analysis were used to elucidate the cytotoxicity of SiNWs. The results showed that the cytotoxicity of SiNWs is greatly dependent on cell lines, SiNWs concentration, and incubation time. Particularly, SiNWs show better biocompatibility with tumor cell lines (eg, human epithelial cervical cancer [Hela] cells and human hepatocellular liver carcinoma [HepG2] cells) than normal cell lines (eg, human normal liver [HL-7702] cells and human embryonic kidney [HEK293T] cells). The reasons may be that SiNWs could tightly attach to the cell membrane in the cell medium, which obviously affects cell adhesion and inhibits their cell viability, especially for normal cell lines. From systematical analysis and comparison, we obtain the concentration limits of SiNWs, which may advance SiNWs applications and its toxicological study in vitro.