Selenium Nanoparticles Stabilized by β-Glucan Nanotubes from Black Fungus and Their Effects on the Proliferation, Apoptosis, and Cell Cycle of HepG2 Cells.

Selenium nanoparticles (Se NPs) have significant anticancer effects, but their poor water solubility and dispersibility limit their further applications in biomedical fields. Biomacromolecules have often been used as dispersants or stabilizers in synthesized Se NPs because they can enhance the dispersibility of Se NPs and reduce their side effects. Our previous studies reported a triple-helix β-glucan (BFP) from the fruiting bodies of black fungus, which showed a good self-assembly ability in constructing hollow nanotubes for loading metal nanoparticles. Therefore, in the present work, BFP nanotubes were designed as carriers to entrap large amounts of Se NPs in order to enhance their stability and anticancer effects. The results showed that Se NPs were successfully synthesized and loaded inside the BFP nanotubes, and the composite (BFP-Se) exhibited high stability and dispersibility due to the covalent Se-O bonds between the Se NPs and the hydroxyl groups on the BFP nanotubes. Moreover, BFP-Se showed significant effects on the proliferation, apoptosis, and cell cycle of HepG2 cells compared to those exhibited by Se NPs. The mechanism was associated with BFP, which acted as a dispersant or stabilizer, resulting in the enhanced cellular uptake of the Se NPs. BFP also activated the death receptor-mediated and mitochondria-mediated apoptotic pathways in HepG2 cells. These results suggest that BFP-Se has potential applications in biomedical fields, especially for the treatment of human liver cancers.