Magnetic-Plasmonic Au@Fe₃O₄ Nanostars Induced Non-Apoptotic Cell Death During Photothermal Therapy

In this study, we present our previously fabricated star-shaped magnetic-plasmonic Au@Fe₃O₄ nanostars as promising agents for photothermal therapy. The nanostars exhibit a photothermal conversion efficiency of ~60% at a concentration of 25 μg/mL under 808 nm laser irradiation. WST-1 analysis revealed that Au@Fe₃O₄ nanostars moderately reduced the viability of human hepatocarcinoma Huh7 cells after 24 h exposure at concentrations of 1, 5, and 10 μg/mL, accompanied by notable morphological alterations. Flow cytometry demonstrated that treatment with 5 μg/mL nanostars followed by 20 min of laser irradiation resulted in 79% elimination of cancer cells. Furthermore, photothermal therapy increased cellular granularity, with highly granulated cells comprising 23% of the population compared to 4% in untreated controls. The viability of these highly granulated cells decreased to 17% post-treatment. Interestingly, photothermal therapy reduced the proportion of apoptotic cells among Huh7 subpopulations relative to the overall number of dead cells.