Nanoparticle Toxicity Assessment in 661W-A11 Cells

Toxicity of NPs was assessed as previously published [57 (link)]. Briefly, 661W-A11 cells were cultured in 96-well plates at a density of 6000 cells/well and increasing dilutions of NPs were added to the culture medium. After 48 or 72 h, the medium was aspirated and the cells in each well were incubated for 2 h at 37 °C with 50 µL of 1 mg/mL 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) diluted in the culture medium. The supernatant was removed and the purple formazan crystals were dissolved in 100 µL of isopropanol and shaken for 10 min. Lastly, the optical density (OD) was measured at 570 nm using a microplate reader (Labsystems Multiskan MCC/340, Fisher Scientific, Rodano, Italy).