Influence of bismuth selenide nanoparticles on cell mitochondrial activity: implications for cancer therapy.

Nanoparticles are promising agents in cancer therapy, yet their cytotoxic mechanisms across diverse cell types require insightful investigation. Bismuth selenide (Bi2Se3) nanoparticles (NPs) was prepared via solvothermal route. The X-ray diffraction (XRD) analysis confirmed that the hexagonal structure with space group R-3 m of the prepared material. The Bi₂Se₃ nanoparticles was found to have a crystallite size of approximately 15 nm. The average NP (powder grain) size and crystallite grain size were determined using Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) techniques. The study examines the cytotoxicity and mitochondrial impact of Bi₂Se₃ NPs in tongue cancer cells (SCC-25) and gingival fibroblasts. After 24 h of exposure, significant reductions in cell viability were observed in both cell types, with heightened sensitivity in gingival fibroblasts. Our findings suggest that the reduced crystallite grain size enhances cytotoxicity, likely due to increased nanoparticle-cell interaction and mitochondrial disruption, with cell-specific responses indicating varied vulnerability to mitochondrial toxicity. These results emphasize the critical role of NP size and crystallite size, and their cell-selective interactions in developing targeted and safe Bi₂Se₃-based therapies for cancer treatment.