2.1.2. Cell Proliferation

Cell viability was determined by a Cell Counting Kit-8 (Beyotime, Shanghai, China). The MC3T3-E1 cells were seeded at 2 <sup>×</sup> 10<sup>3</sup> cells per well in 96-well culture plates for 24, 48, and 72 h. At the above time points, the cells were washed twice with PBS solution, and 250 μL fresh culture medium with 25 μL CCK-8 reagent was sequentially added to each sample. After incubation for 2 h at 37 ◦C, 100 μL medium was transferred to a 96-well plate and measured at 450 nm by using a micro-plate reader (Infinite M200, Tecan, Männedorf, Switzerland).
