*2.6. Quantitative Phase Imaging (QPI) Microscopy*

For QPI analysis, cells were seeded in a 96-well plate (Corning, Tewksbury, MA, USA) at 4 <sup>×</sup> <sup>10</sup><sup>3</sup> per well. After 24 h, the cells were treated at the same concentrations used for the MTT assays. QPI was performed by a Livecyte microscope (Phase Focus, Sheffield, UK). Images were acquired every 60 min for 3 days using a 10× objective (0.25 NA) at 37 ◦C and 5% CO2. QPI data were analyzed using Cell Analysis Toolbox software (Phase Focus, Sheffield, UK). We evaluated cell doubling time, displacement, dry mass, sphericity to assess cell vitality, and differentiation.
