2.8. Cell Viability Analysis

The protective properties of drug-associated nanocarriers against rotenone-induced reduction in cell viability was assessed using the MTT Assay, as previously described [42]. Briefly, following the 24 h rotenone treatment in 96-well plates, SH-SY5Y cells were incubated with an additional 20 μL of 5 mg/mL MTT DPBS solution for 4 h at 37 °C. Following aspiration, 100 μL of DMSO was added to each well to dissolve the formazan crystals. To ensure that DMSO was mixed well, plates were placed on a MaxQ 4000 benchtop orbital shaker (Thermo Fisher Scientific, UK) at 75 rpm for 15 min and the absorbance was read at 570 nm using a spectrophotometer.