“…9,10 The first step of transforming MSCs into cartilage is cellular condensation, which is important for the signal activation of cartilage differentiation. 11,12 However, the traditional 2-dimensional (2D) monolayer culture is less effective for the chondrogenesis of MSCs than the 3-dimensional (3D) culture system because the cell interaction is not enough in the 2D monolayer culture. 13 The 3D culture can mimic the progress of precartilage condensation during the development of the limb.…”