RESUMO
BACKGROUNDS AND AIMS: Selenium nanoparticles (SeNPs) have been reported to exhibit an inhibitory effect on cancer cells. In the present study, we aimed to compare the in vitro and in vivo effects of SeNPs and folic acid surface-coated selenium nanoparticles (FA@SeNPs) on breast cancer. METHODS: FA@SeNPs and SeNPs were chemically synthesized and characterized with different instrumental techniques. The cytotoxicity of both nanomaterials was evaluated against 4T1 cells. In addition, the intravenous administration effect of these nanomaterials (300 µg/week) on the lifespan and tumor size of cancer-bearing mice was investigated. RESULTS: Although the SeNPs showed an antiproliferative effect against the cell line, the cytotoxicity of the FA@SeNPs was higher than that of the SeNPs. A low concentration of FA@SeNPs (25 µg/mL corresponding to 8.75 µg/mL of elemental SeNPs) caused approximately 68% cell mortality. In the in vivo study, the nanomaterials decreased the tumor growth rate in cancerous mice in relation to the control group. FA@SeNPs were more effective than SeNPs. CONCLUSIONS: The combination of SeNPs and FA has a potent antiproliferative effect against 4T1 cells, significantly increases the lifespan, and prevents tumor growth.